Water-back construction for furnaces.



F. A. HURLBUT. WATER BACK CONSTRUCTION FOR FURNACES.

APPLICATION FILED JUNE 24. 1916.

1,269,083. Patend'grune 11, 1918.

FRANK A. I-IURLBUT, OF KANSAS CITY, MISSOURI.

WATER-BACK CONSTRUCTION FOR FURNACES.

Specification of Letters Patent. Patented June 11, 1918.

Application led June 24, 1916. Serial No. 105,725.

To all whom t may concern.'

Be it known that I, FRANK A. HUnLBU'r, a citizen of the United States, residing at Kansas City, in the county of Jackson, State of Missouri, have invented certain new and useful Improvements in Water-Back Constructions for Furnaces, of which the following is a. full and exact specification.

The present invention relates to improvements in furnaces, with particular reference to boiler furnaces, and aims to devise an improved construction of wateir back br water circulating member at the bridge wall end of the lire chamber. To this end, a water circulating member is provided in the required position, and in this connection it is an object of the invention to further increase the life or durability of this waterv back member by a novel arrangement and construction of the same whereby a more rapid water flow is produced past those portions of the member which are subjected to the strongest heat influence, so that the efficiency of the member as regards transfer of heat is likewise promoted.

It is also an object to provide such a construction that the quickening ofthe water flow at the required points will enable a smaller quantity of water or equivalent fluid to be used as a circulating medium, and without materially decreasing the volumetric capacity of the member itself.

1 For carrying out the purposes of the invention, a construction has been devised in which the fluid containing casing is provided with means for causing the flow therethrough to follow principally a course along the walls which are chiefly exposed tothe f specification.

direct action of the heat, and it may be pointed out that thei novel features in this relation niay'lind other analogous uses not specially dwelt upon or emphasized in this With the foregoing general objects in view, the invention will now be describedv with reference to the accompanying drawing, illustrating one form of embodiment of v the invention, after which those features and combinations of parts deemed to be novel will be severally set forth and defined in the appended claims.

In the drawing- Figure 1 is a vertical longitudinal sectional view of a portion of a boiler furnace fire chamber, illustrating the application of my improved water back construction.

lFig. 3 is a transverse section on the line- III-III, on a still larger scale; and

Fig. 4 is a similar sectional view illustrating the construction as embodied in a designdiffering only in vform of cross-section.

Referringto the drawing in detail, this illustrates1 the water back or water circulating member as comprising an outer tubular water casing 2, within which is centrally arranged a. feed water tube 4 extending longitudinally through the casing 2 and provided at lits outer end with ay feed water passage 6, the casing 2 having one end-closed by the cap 8 and its otherend provided with the outlet passage 10. The, feed tube 4 may be formed with the exterior thread 12` for adjustable mounting of a series of correspondingly threaded baffle elements 14, which may be clamped in their proper spaced relation by means of lock nuts 16. These baflle elements are formed with the spacing lugs 18` for engagement with the interior face of the.

represented as circular in Fig.` 3, and as square in Fig. 4.

` Fig. 1 illustrates the relation in which the water back or water circulating member, as thus constructed, is specially designed for use, this being in' connection with the overhanging portion of the bridge wall 20of` a furnace and at the point overlying the air passage 22 at the ash end of the stoker convcyer 24. g This portion of the bridge wall is particularly subject to the destructive action of thel heat of the furnace, requiring repeated renewal, since the air passage 22, for proper combustion, must be kept always at practically the same size and not allowed to admit more than just the required volume of air. The cooling action of the water passing through the water back or circulating member serves to keep down vthe temperature upon the flame side of the casing 2, as will be readily understood. In the absence of any baille construction, however, the

friction. of the relatively large surface of the outer casing walls would retard the flow ofl ratus, and for directing said flow chiefly` along the inner face of the outer casing 2;

and preferably, as shown in Figs. 1, 3, and

4, said baffle elements are arranged eccentrically within said casing, since but one side of the casing is exposed directly to the fire chamber and it is hence sufficient to quicken the water flow on that side only.

It will thus be apparent that avsimple and efficient arrangement and construction has been devised for fulfilling the objects of the invention. A substantial increase in the rate of water flow is produced at the required points for accelerating the heat transfer and preserving the parts most severely subjected to the heat, and this is done without materially decreasing the volumetric capacity of the circulating member. Moreover, since the direction of the water flowl along` the described course, and the rate of said flow, are such as to be adapted to secure the most eflicient transfer` of heat at the flame side of the apparatus, it will be seen that a lesser quantity of fluid will be required for the circulating medium.

While the foregoing represents what is now deemed to constitute the preferred form of embodiment of the invention, the right is reserved to such formal changes and modilications as may fairly fall within the scope of the following claims.

Claims:

l. ln a furnace wall construction, a water back member comprising an outer casing mounted with one side thereof exposed to the flame side of the wall, a feed tube mounted longitudinally within said casing, and baffle elements mounted in the space between said casing and feed tube and arranged in position to direct the flow of water in a path along the flame side of said casing.

2. ln a furnace bridge wall construction, a water back member comprising an outer casing mounted with one side thereof exposed to the flame side of the bridge wall, a feed tube mounted longitudinally Within said casing, and a series of spaced baffle plates mounted at right angles to the axis of the feed tube and in the space between the'latter and said'casing in position to di- 60 rect the flow of water in a path along the inner face of' the flame side of said outer casing.

3. In a furnace bridge wall construction, a water back member comprising an outer casing mounted with one side thereof exposed to the flame side of the bridge wall, a feed tube mounted longitudinally within said casing, and baffle elements mounted in the space between said casing and feed tube, 7 0 said baffle elements having each a contour of substantially the same form as the cross-section of said casing and arranged in position to direct the flow of water in a path along the inner face of thev flame lside of said casino:

et. In a furnace bridge wall construction, a water back member comprising an outer casing mounted with one side thereof exposed to the flame side of the bridge wall, a feed tube mounted longitudinally within said casing, and a series of spaced baffle elements mounted inthe space between said casing and feed tube, said baffle elements having each a contour of substantially the same form as the cross-section of said casing and carried eccentrically within the latter in position to direct the flow of water in a path along the inner face of the flameside of said outer casing.

5. In a furnace bridge wall construction, a water back member comprising an outer casing mounted with one side thereof exposed to the flame side of the bridge wall, a feed tube mounted longitudinally within said casing, and baillie elements 4mounted in the space between said casing and feed tube, said elements being of a contour of the same form as the cross-section of the casing and mounted eccentrically within the latter with one side of each of said elements in contact with the casing on the side opposite the flame side of the casing, whereby the flow of water is directed in a path along the inner face of the flame side of saidcasing.

' FRANK A. HURLBUT.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of @atenta Washington, D. C. 

